Sudden Cardiac Arrest (SCA) is a leading single cause of death in this country. Between 350,000 and 450,000 individuals a year, or more than 1000 per day, fall victim to this disease, despite 4 decades of education and systematic interventions, survival rates have not improved: about 95% of SCA victims will die.
One of the aspects of caring for a victim of SCA is the critical importance of time. SCA occurs suddenly, with little or no warning: the victim simply collapses and blood flow to the heart and brain stops abruptly. The window for initiating treatment is measured in minutes—few survive if treatments are delayed beyond 8-10 minutes. The victim is, therefore, totally dependent upon the actions of those who witness the cardiac arrest. This is, in turn, influenced by the location of the event: 15-20% occur in public places (where witnesses are more likely to be present) while the remaining 80-85% occur in private locations, the most common being sites of residence, where 40% of events are unwitnessed. Survival rates for unwitnessed events are uniformly almost zero.
When an event is witnessed by a layperson, interventions become available that dramatically improve survival: recognition of the event as a cardiac arrest, activation of the EMS system by calling 911, and provision of “CPR” until help arrives. Recognizing a collapse as a possible SCA depends almost totally upon educational programs aimed at the layperson. Calling for help as soon as possible after recognition may be critical because the majority of survivors of SCA have a cardiac rhythm that responds to defibrillation. Education is also the primary modality for improving performance in this activity; but in specialized settings (e.g. industry, schools, sports events, etc.), pre-planned methodologies similar to fire drills could be developed.
A witness who performs “CPR” dramatically increases the odds of survival. In fact, it is the single most valuable contribution to survival, increasing odds of success up to 4.5. fold. Some witnesses have received training in CPR but even in communities with decades of public education, the percentage of individuals trained is rarely over 30%. Typically only 15% are trained.
Simplification of layperson (and/or initial responder) CPR training to include only activities that are crucial to survival at the time of their contact with the patient (i.e. to “call 911” and “provide chest compressions”) should improve the number of willing and competent persons. This simplification should also result in more “CPR” actually being delivered to victims because the breathing component in traditional “CPR” in not only difficult to teach and recall but very difficult to perform adequately. Having to breathe for SCA victims results in many witnesses forgoing any CPR activities.
Evidence also indicates that breathing may not only be unnecessary in the initial minutes of an arrest but the effort is indeed detrimental because it takes valuable time away from the crucial activity of circulating blood to the brain and heart. See, for example, “Cardiocerebral resuscitation: a new approach to out-of-hospital cardiac arrest,” Ewy, Gordon A. and Kellum, Michael J., University of Arizona Sarver Heart Center, University of Arizona, Tucson, Ariz., American Heart Association, Dec. 10, 2004. See also, “Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-KANTO): an observational study,” The Lancet, Mar. 17, 2007.